JP2012097642A - Fuel injection valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel injection valve that promotes formation of thin membranes of fuel within injection holes and promotes atomization of spray is obtained.SOLUTION: Holes provided in an injection hole plate 11 are combined injection holes 16 formed by partially overlapping two or more single injection holes 15a, 15b, 15c from an upstream side to a downstream side of the injection hole plate 11, each of the single injection holes is a circular hole, the single injection hole has an injection hole angle α defined by a tilt angle of a center axis line connecting an entrance part center and an exit part center relative to a plate thickness direction of the injection hole plate 11, areas of exit parts 16b are larger than areas of entrance parts 16a in the combined injection holes 16, and the combined injection holes 16 are formed by press working.

Description

  The present invention mainly relates to a fuel injection valve used in a fuel supply system of an internal combustion engine, and particularly relates to an injection hole plate provided on the downstream side of a valve seat.

  In recent years, as exhaust gas regulations for automobiles and the like have been strengthened, improvement in the degree of freedom and atomization of the direction of fuel spray injected from the fuel injection valve has been demanded. Various studies have been made.

  In a conventional fuel injection valve, there is known a fuel injection valve in which a thin injection hole plate having a plurality of injection holes formed on a fuel downstream side of a valve member and a valve seat is disposed and fuel is injected from each injection hole. Yes. In such a fuel injection valve, generally, the nozzle hole has the same diameter from the inlet to the outlet, and when the fuel flows into the nozzle hole of the same diameter, the fuel moves along the inner peripheral surface of the nozzle hole. It is sprayed as a liquid column without spreading. The fuel that has become such a liquid column is not easily atomized, and deteriorates combustion in the internal combustion engine.

  On the other hand, it is conceivable to taper the nozzle hole in order to obtain a liquid film sufficiently expanded in the nozzle hole as disclosed in, for example, JP-A-2001-317431. By adopting a conical shape in which the outlet side of the nozzle hole expands, it can be expected that the spray spreads sufficiently along the inner wall surface of the nozzle hole and the fuel is injected in a thin film.

  Further, as shown in, for example, Japanese Patent Application Laid-Open No. 2006-2720, the fuel inlet has an elliptical shape or a plurality of circular shapes, and fuel is injected from a strip-like outlet smoothly communicated with the inlet, It is said that a uniform liquid film-like spray can be injected from the outlet and promote atomization of fuel.

  Further, as shown in, for example, Japanese Patent Application Laid-Open No. Hei 8-200187, the nozzle hole shape is a straight and elongated shape, and an oval nozzle hole having a major axis and a minor axis each having an arc shape at both ends, and the minor axis is reduced. By doing so, the fuel spray can be atomized. Further, as a modification of the oval type nozzle hole, there is one in which one nozzle hole is formed by overlapping three circular nozzle holes on a straight line.

JP 2001-317431 A (paragraph 0019, FIG. 4) JP 2006-2720 A (paragraph 0061, FIG. 9, FIG. 11) Japanese Patent Laid-Open No. 8-200177 (paragraph 0021, FIGS. 1 and 5)

  However, when a tapered nozzle hole as shown in Patent Document 1 is formed on the nozzle hole plate, the area of the nozzle hole inlet on the processing tends to vary, so there is a problem that the flow rate and spraying vary, Since a very complicated process is required for manufacturing and dimensional control, there is a problem that productivity of the fuel injection valve is deteriorated and cost is increased.

  In addition, the nozzle holes as shown in Patent Document 2 and Patent Document 3 have a structure in which spray having a shape along the flow path shape is injected while fuel is filled in the nozzle hole. Bubbles in fuel generated by boiling under reduced pressure on the upstream side of the nozzle hole are clogged at the nozzle hole outlet, and there is a problem that the flow characteristics (static flow and dynamic flow) change greatly due to changes in temperature, atmospheric pressure, etc. .

  The fuel injection valve according to the present invention solves the above-mentioned problems, facilitates manufacture, promotes thinning of the fuel in the nozzle hole, promotes atomization of the spray, and attempts to reduce the change in flow characteristics. To do.

  The fuel injection valve according to the present invention has a valve body that opens and closes a valve seat, and by opening the valve seat with the valve body, fuel passes between the valve body and a seat surface of the valve seat, In the fuel injection valve that is injected from a plurality of holes provided in the injection hole plate mounted on the downstream side of the valve seat, the hole provided in the injection hole plate includes two or more single injection holes. The combined injection holes are formed so as to overlap each other from the upstream side to the downstream side of the hole plate, and each single injection hole has the same diameter at the upstream side inlet portion and the downstream side outlet portion. At least one of the single nozzle holes has a nozzle hole angle α defined by an inclination angle of a central axis connecting the inlet center and the outlet center with respect to the nozzle plate thickness direction. And the central axis of each single nozzle hole forming the united nozzle hole is orthogonal to the valve seat axis By having an intersection angle β so that the central axes of each single nozzle hole intersect when projected onto a surface, the area of the outlet part is larger than the area of the inlet part in the coalesced nozzle hole, and The coalesced injection hole is formed by pressing.

  According to the fuel injection valve of the present invention, the united injection hole is formed by overlapping two or more single injection holes, which are circular holes, partially overlapping from the upstream side to the downstream side of the injection hole plate. The manufacturing is easy, and the area of the inner peripheral surface of the united injection hole is increased toward the outlet side. Therefore, the fuel thinning in the united injection hole proceeds and the atomization of the spray can be promoted. Moreover, various spray shapes can be realized without sacrificing atomization depending on the shape of the united nozzle hole to be formed. In addition, even if a part of the fuel boiled under reduced pressure and bubbles are generated in the fuel, when the fuel enters from the inlet of the coalesced injection hole, it is pressed against the inner wall surface of the coalesced injection hole to form a thin liquid film, Compared to the nozzle hole with the same diameter from the nozzle hole inlet to the outlet, the area of the inner peripheral surface of the combined nozzle hole increases toward the outlet side, so that bubbles can easily escape from the combined nozzle hole, and the atmosphere changes The change in the flow rate characteristics (static flow rate / dynamic flow rate) associated with can be reduced.

It is sectional drawing of the fuel injection valve in Embodiment 1 of this invention. FIG. 3 is a view showing an injection hole plate portion at a tip portion of the fuel injection valve of the first embodiment. It is a figure which shows the nozzle hole plate part in the front-end | tip part of the fuel injection valve of Embodiment 2. FIG. FIG. 6 is an explanatory diagram showing a state of fuel injection to an intake port and an intake valve in a fuel injection valve of a second embodiment. FIG. 10 is a view showing an injection hole plate portion at a tip portion of a fuel injection valve according to a third embodiment. FIG. 10 is a view showing an injection hole plate portion at a tip portion of a fuel injection valve according to a fourth embodiment. It is a figure which shows the nozzle hole plate part in the front-end | tip part of the fuel injection valve of Embodiment 5. FIG. FIG. 10 is a view showing an injection hole plate portion at a tip portion of a fuel injection valve according to a sixth embodiment. FIG. 10 is a view showing an injection hole plate portion at a tip portion of a fuel injection valve according to a seventh embodiment. FIG. 10 is a view showing an injection hole plate portion at a tip portion of a fuel injection valve according to an eighth embodiment.

Embodiment 1 FIG.
1 is a sectional view showing a fuel injection valve according to Embodiment 1 of the present invention. In the figure, a fuel injection valve 1 includes a solenoid device 2, a housing 3 that is a yoke part of a magnetic circuit, a core 4 that is a fixed core part of the magnetic circuit, a coil 5, an armature 6 that is a movable core part of the magnetic circuit, and a valve. A device 7 is included. The valve device 7 includes a valve body 8, a valve body 9 and a valve seat 10. The valve body 9 is welded after being press-fitted into the outer diameter portion of the core 4. The amateur 6 is welded after being pressed into the valve body 8. An injection hole plate 11 is joined to the valve seat 10 after being inserted into the valve body 9 in a state where it is joined to the downstream side of the valve seat by a welded portion 11a, and then joined by a welded portion 11b. The nozzle hole plate 11 is provided with a plurality of holes 12 penetrating in the plate thickness direction.

Next, the operation will be described. When an operation signal is sent from the engine control device to a drive circuit (not shown) of the fuel injection valve 1, a current is passed through the coil 5 of the fuel injection valve 1, and the armature 6
Magnetic flux is generated in a magnetic circuit composed of the core 4, the housing 3, the valve body 9, and the armature 6, the armature 6 is attracted to the core 4 side, and the upper surface 6a of the armature 6 comes into contact with the lower surface of the core 4. When the valve body 8, which is an integral structure with the amateur 6, is separated from the valve seat surface 10 a and a gap is formed, the fuel is removed from the plurality of grooves 13 a provided at the tip (ball) 13 of the valve body 8. The air is injected from the plurality of holes 12 into the engine intake pipe through the gap between the surface 10a and the valve body 8.

  When an operation stop signal is sent to the drive circuit of the fuel injection valve 1 from the engine control device, the current supply from the connector 51 to the coil 5 is stopped, the magnetic flux in the magnetic circuit is reduced, and the valve body 8 is closed. Due to the elastic force of the compression spring 14 being pushed in the valve direction, the gap between the valve body 8 and the valve seat surface 10a is closed, and fuel injection is completed. During the opening / closing operation of the valve body 8, the valve body 8 slides with a guide portion 9a protruding inward in the radial direction of the valve body 9, and the guide portion 13b of the ball 13 of the valve body 8 It slides with the moving part 10b. The guide portion 13b is a means for regulating the non-coaxiality (swing) in the radial direction of the valve body 8 with respect to the valve seat sliding portion 10b. Therefore, the clearance is preferably set as small as possible, and is set to 10 μm or less (one-side clearance of 5 μm or less) in order to keep the durable wear of the valve body 8 within an allowable limit.

  2A and 2B are diagrams showing an injection hole plate portion at a tip portion of the fuel injection valve of Embodiment 1, in which FIG. 2A is a cross-sectional view, and FIG. (C) is a three-dimensional explanatory drawing of the A section of (b) figure. The plurality of holes 12 in the injection hole plate 11 of the fuel injection valve 1 of Embodiment 1 are formed as follows. As shown in FIGS. 2B and 2C, the three single injection holes 15a, 15b, and 15c are partially divided from the upstream side (upstream surface) to the downstream side (downstream surface) of the injection hole plate 11. Thus, the united nozzle hole 16 is formed. The single injection holes 15a, 15b, and 15c are circular holes (cylindrical holes) having the same diameter from the upstream inlet portion to the downstream outlet portion of the injection hole plate 11, and the three single injection holes 15a, 15b, The diameter of the central single injection hole 15b is larger than that of the other two single injection holes 15a and 15c, and the single injection holes 15a, 15b and 15c It has a nozzle hole angle α defined by an inclination angle of a central axis connecting the center of the nozzle and the center of the outlet with respect to the nozzle hole plate thickness direction. The single nozzle hole 15a and the single nozzle hole 15c have the same hole diameter.

  When the central axis of the single injection holes 15a, 15b, and 15c is projected onto a plane orthogonal to the valve seat axis 34 so that the area of the exit part is larger than the area of the inlet part of the combined injection hole 16 In addition, there is a predetermined angle β between adjacent single nozzle holes so that the central axes of the single nozzle holes 15a, 15b, 15c intersect each other. The angle between the single nozzle holes 15a, 15b and the angle between the single nozzle holes 15b, 15c need not be the same, and the central axes of the single nozzle holes 15a, 15b, 15c need to intersect at one point. Absent.

  The main flow of the fuel flow from the valve seat surface 10a flows into the inlet 16a of the coalesced injection hole 16 from the radially outer side to the inner side of the valve seat shaft 34 of the fuel injection valve, and the inlet part of the coalesced injection hole 16 A liquid film is formed by the separation of the flow at 16a, the fuel is pressed in the direction of the valve seat shaft 34 in the united injection hole 16, and the flow in the united injection hole 16 becomes a flow along the curvature of the united injection hole 16. It is configured to be injected from the outlet portion 16 b of the united injection hole 16. In the first embodiment, all the holes forming the combined injection hole 16 have the injection hole angle α, but at least one of the plurality of single injection holes forming the combined injection hole 16 is the above-described one. It suffices to have a nozzle hole angle α.

  The united injection hole 16 is formed by pressing the single injection holes 15a, 15b, and 15c on the hole plate 11 and combining the circular holes of the single injection holes 15a, 15b, and 15c. Or you may press into the shape of the united injection hole 16. FIG. In any case, since the united injection hole 16 is formed by combining circular holes, manufacture is easy.

  The fuel injection valve in the first embodiment is configured as described above, and the area of the inner peripheral surface of the combined injection hole becomes larger toward the outlet side than the injection hole having the same diameter from the injection hole inlet to the outlet. Therefore, the fuel thinning in the coalesced injection hole is promoted toward the outlet portion 16b, and atomization of the spray becomes possible. Further, as described above, since the fuel is not filled in the coalesced nozzle hole, the fuel is injected into the coalesced nozzle hole 16 as a thin liquid film while being pressed into the coalesced nozzle hole. It has a structure in which bubbles generated in the holes 16 are easily removed, and it is possible to reduce the change in flow rate characteristics (static flow rate / dynamic flow rate) accompanying the change in atmosphere.

Embodiment 2. FIG.
FIG. 3 is a view showing an injection hole plate portion at a tip portion of a fuel injection valve according to Embodiment 2, in which (a) is a cross-sectional view, (b) is a plane explanatory view of FIG. (C) is a three-dimensional explanatory diagram of part B of FIG. (B), and (d) is an explanatory diagram showing the state of fuel in the fistulas of parts B and C of FIG. The plurality of holes 12 in the injection hole plate 11 of the fuel injection valve 1 according to Embodiment 2 are formed as follows. Three single injection holes 17a, 17b, and 17c are continuously overlapped from the upstream side (upstream surface) to the downstream side (downstream surface) of the injection hole plate 11 to form a combined injection hole 18. .

  The single injection holes 17a, 17b, and 17c are circular holes (cylindrical holes) having the same diameter from the upstream inlet portion to the downstream outlet portion of the injection hole plate 11, and the three single injection holes 17a, 17b, The pore diameters of 17c are different from each other. (B) In the case of part B in the figure, the diameter of the single nozzle hole gradually decreases from the top to the bottom of the paper, and in part C, the diameter of the single nozzle holes 17a, 17b, and 17c from the top of the paper. It gradually increases toward the bottom. Each of the single injection holes 17a, 17b, and 17c has an injection hole angle α defined by an inclination angle of the central axis connecting the inlet center and the outlet center with respect to the injection hole plate thickness direction. However, the nozzle hole angles α of the single nozzle holes 17a, 17b, and 17c may be different. The other configuration is the same as that of the first embodiment. The area of the outlet is larger than the area of the inlet in the united injection hole 18, and the united injection hole 18 is formed by combining circular holes. Therefore, manufacture is easy.

  By forming different coalesced injection holes 18 (B part, C part) as shown in FIG. 3, the way of spreading the fuel in the coalesced injection holes 18 is not uniform {see FIG. Fuel is injected while having a difference in the liquid film thickness of the fuel. By arranging a plurality of different coalesced injection holes 18 in the nozzle hole plate 11 and forming one collective spray by the coalesced nozzle hole group, in the concentration distribution and the shape in one collective spray, Various variations are possible.

  In general, the spray angle formed by the ridge line of the collective spray (hereinafter referred to as spray angle) and the particle size of the collective spray are in a trade-off relationship, and the larger the spray angle, the smaller the particle size. In a fuel-injection internal combustion engine, ignition is completed quickly by supplying atomized fuel, combustion efficiency is increased, and exhaust gas concentration, particularly hydrocarbon HC emission concentration is reduced. To increase the fuel, it is necessary to atomize the fuel.

  In a conventional fuel injection valve, a spray having a substantially uniform particle size in a collective spray is injected aiming at an intake valve, and at that time, a portion outside the center axis of the spray is a certain amount of intake air. Adhering to the inner wall of the port. In order to atomize the collective spray having a substantially uniform particle size as described above, if the spray angle is increased, the adhesion to the inner wall of the intake port is increased, and a liquid film is transmitted along the inner wall and delayed into the cylinder. As the amount of fuel flowing in increases, the combustion efficiency decreases. As a result, the concentration of hydrocarbon HC in the exhaust gas increases, and the engine controllability deteriorates.

  FIG. 4 is an explanatory view showing a state of fuel injection to the intake port and the intake valve in the fuel injection valve of the second embodiment, and (a) is a cross-sectional explanatory view of the intake port and the intake valve portion, (b) (A) It is the upper surface explanatory view of the C view of figure. In the second embodiment, the fuel in the coalesced injection holes 18 is formed into a liquid film in a non-uniform manner compared to the conventional example, so that the particle size distribution in the collective spray formed by the injection from the coalesced nozzle holes is obtained. As shown in FIG. 4, a portion 19 a having a small particle size is formed on the outside of the collective spray, and a portion 19 b having a large particle size at the sacrifice of atomization is formed on the inside in order to atomize the outside, as shown in FIG. Combustion efficiency can be improved by quickly evaporating by applying the large-diameter portion 19b to the high-temperature intake valve central portion 20 and reducing the adhesion to the intake port inner wall 21 in the outer spray. It is.

Embodiment 3 FIG.
FIG. 5 is a view showing an injection hole plate portion at a tip portion of a fuel injection valve according to Embodiment 3, in which (a) is a cross-sectional view, (b) is a plane explanatory view of FIG. (C) is a three-dimensional explanatory drawing of the D section of (b) figure. The plurality of holes 12 in the injection hole plate 11 of the fuel injection valve 1 according to Embodiment 3 are formed as follows. As shown in FIGS. 5B and 5C, the three single injection holes 23a, 23b, and 23c are partially divided from the upstream side (upstream surface) to the downstream side (downstream surface) of the injection hole plate 11. Thus, the united nozzle hole 22 is formed. The single nozzle holes 23a, 23b, and 23c are circular holes (cylindrical holes) having the same diameter from the upstream inlet portion to the downstream outlet portion of the nozzle plate 11, respectively. The area of the inlet portion 22a in the combined nozzle hole 22 is the same as the area of the inlet portion of the single nozzle hole 23b having the largest bore diameter among the three single nozzle holes 23a, 23b, 23c forming the combined nozzle hole 22. It is formed to become. Therefore, the diameters of the other two single nozzle holes 23a and 23c are equal to or smaller than the diameter of the single nozzle hole 23b.

  Other configurations are the same as those of the first embodiment, and the single injection holes 23a, 23b, and 23c are defined by inclination angles of the central axis connecting the inlet center and the outlet center with respect to the injection hole plate thickness direction. Since the area of the exit portion is larger than the area of the entrance portion in the merged nozzle hole 22 and the merged nozzle hole 22 is formed by combining the circular holes, Easy to manufacture. In the single nozzle holes 23a, 23b, and 23c, the nozzle hole angles α may be different from each other.

In addition,
Also in the third embodiment, as in the first embodiment, atomization of the fuel spray can be promoted, and the area of the inlet portion 22a in the combined injection hole 22 is set to the maximum of the three single injection holes 23a, 23b, and 23c. By making it the same as the area of the inlet portion of the single nozzle hole 23b having the hole diameter, it is possible to suppress the flow rate variation due to the processing position variation of the other single nozzle holes 23a and 23c.

Embodiment 4 FIG.
6A and 6B are views showing an injection hole plate portion at a tip portion of a fuel injection valve according to Embodiment 4, in which FIG. 6A is a cross-sectional view, and FIG. 6B is an explanatory plan view of FIG. (C) is a three-dimensional explanatory drawing of the E section of (b) figure. The plurality of holes 12 in the injection hole plate 11 of the fuel injection valve 1 according to Embodiment 4 are formed as follows. As shown in FIGS. 6B and 6C, the three single injection holes 25a, 25b, and 25c are continuously divided from the upstream side (upstream surface) to the downstream side (downstream surface) of the injection hole plate 11. Thus, a united nozzle hole 24 is formed. The single injection holes 25a, 25b, and 25c are circular holes (cylindrical holes) having the same diameter from the upstream inlet portion to the downstream outlet portion of the injection hole plate 11, respectively. The diameters of the three single injection holes 23a, 23b, and 23c are all the same, and the injection hole angle α described in the first embodiment is the same as that of the three single injection holes 23a, 23b, and 23c. It may be.

  Other configurations are the same as those of the first embodiment, and the area of the outlet portion is larger than the area of the inlet portion in the united injection hole 24, and the united injection hole 24 is formed by combining the circular holes. Easy to manufacture. Furthermore, the arrangement | positioning of the inlet part of single injection hole 25a, 25b, 25c is piled up, and the area of the inlet part in the united injection hole 24 corresponds with the area of the inlet part of a single injection hole.

  By forming the coalesced injection hole 24 as shown in FIG. 6, atomization of the fuel spray can be promoted as in the first embodiment. Further, when the single injection holes 25a, 25b, and 25c are manufactured by press working, if the injection hole diameter is the same and the injection hole angle α is the same, various types of injection hole forming punches are produced during the manufacture. There is no need to prepare, and it can be manufactured at a lower cost than other embodiments.

Embodiment 5 FIG.
FIG. 7 is a view showing an injection hole plate portion at a tip portion of a fuel injection valve according to a fifth embodiment, in which (a) is a cross-sectional view, (b) is a plane explanatory view of FIG. (C) is a three-dimensional explanatory view of the F part of FIG. (B), and (d) is an explanatory view showing the state of fuel in the fistulas of the F part and G part of FIG. The plurality of holes 12 in the injection hole plate 11 of the fuel injection valve 1 according to Embodiment 5 are formed as follows. Two single injection holes 27a and 27b are continuously overlapped from the upstream side (upstream surface) to the downstream side (downstream surface) of the injection hole plate 11 to form a combined injection hole 26.

  The single injection holes 27a and 27b are circular holes (cylindrical holes) having the same diameter from the upstream inlet to the downstream outlet of the injection hole plate 11, and the single injection holes 27a and 27b have the same hole diameter. It is. The single nozzle holes 27a and 27b respectively have nozzle hole angles α1 and α2 defined by inclination angles of the central axis connecting the inlet center and the outlet center with respect to the nozzle plate thickness direction, The nozzle hole angle α1 and the nozzle hole angle α2 are different. The other configuration is the same as that of the first embodiment, and the area of the outlet is larger than the area of the inlet in the united injection hole 26, and the united injection hole 26 is formed by combining circular holes. Therefore, manufacture is easy. Furthermore, the arrangement | positioning of the inlet part of the single injection holes 27a and 27b is piled up, and the area of the inlet part in the united injection hole 26 corresponds with the area of the inlet part of a single injection hole. The diameters of the single nozzle holes 27a and 27b are not necessarily the same.

  By forming the united injection hole 26 as shown in FIG. 7, atomization of the fuel spray can be promoted similarly to the first embodiment, and when the single injection holes 27a and 27b are manufactured by press working, If the hole diameters are the same, it is not necessary to prepare several kinds of punches for forming the nozzle holes at the time of manufacturing, and it can be manufactured at a lower cost than the embodiment in which the hole diameters are not the same. By forming the coalesced nozzle hole 26 as shown in FIG. 7, the liquid film spreads in the coalesced nozzle hole in a manner similar to the second embodiment, and the same effect as in the second embodiment is obtained. be able to.

Embodiment 6 FIG.
FIG. 8 is a view showing an injection hole plate portion at a tip portion of a fuel injection valve according to Embodiment 6, in which (a) is a cross-sectional view, (b) is a plane explanatory view of FIG. (C) is a three-dimensional explanatory diagram of the H part in (b), and (d) is a characteristic showing the relationship between the spray average particle diameter (μm) and the center-to-hole distance ds (mm) at the nozzle hole outlet. FIG. The single injection holes 29a, 29b, and 29c are partially overlapped continuously from the upstream side (upstream surface) to the downstream side (downstream surface) of the injection hole plate 11 to form a combined injection hole 28.

  The single injection holes 29a, 29b, and 29c are circular holes (cylindrical holes) having the same diameter from the upstream inlet portion to the downstream outlet portion of the injection hole plate 11, and the single injection holes 29a, 29b, and 29c. The fistula diameters D are all the same. The single injection holes 29a, 29b, and 29c have the injection hole angle α defined above, and the injection hole angles α may all be the same or different from each other. The other configuration is the same as that of the first embodiment, and the area of the outlet portion is larger than the area of the inlet portion in the united injection hole 28, and the unitary injection hole 28 is formed by combining circular holes. Therefore, manufacture is easy. Furthermore, the arrangement of the inlet portions of the single injection holes 29a, 29b, and 29c is overlapped with each other, and the area of the inlet portion in the combined injection hole 28 coincides with the area of the inlet portion of the single injection hole.

  According to the experiment, when the distance between the centers of the outlets of the adjacent single nozzle holes 29a and 29b is ds (mm), as shown in FIG. (D), the relationship between the spray average particle diameter (μm) and ds is It can be seen that when 0 <ds ≦ D / 2, thinning of the fuel in the coalesced injection hole 28 is promoted, and a desired spray particle size is obtained. Further, when ds> D / 2, it is understood that the portion where the single injection holes intersect inhibits the spread of the fuel in the combined injection holes, and a desired spray particle size cannot be obtained.

Embodiment 7 FIG.
FIG. 9 is a view showing an injection hole plate portion at the tip portion of the fuel injection valve of Embodiment 7, in which (a) is a cross-sectional view, (b) is a plane explanatory view of FIG. (C) is a three-dimensional explanatory diagram of part I of FIG. (B), and (d) is a characteristic showing the relationship between the spray average particle size (μm) and the center-to-hole distance ds (mm) at the nozzle hole outlet. FIG. The single injection holes 31a, 31b, 31c are partially overlapped continuously from the upstream side (upstream surface) to the downstream side (downstream surface) of the injection hole plate 11 to form a combined injection hole 30.

  The single injection holes 31a, 31b, and 31c are circular holes (cylindrical holes) having the same diameter from the upstream inlet portion to the downstream outlet portion of the injection hole plate 11, and adjacent single injection holes 31a, 31b, and The pore diameters of 31b and 31c are different from each other. In the case of Embodiment 7, the diameters of the single nozzle holes 31a and 31c are the same, but may be different. The single injection holes 31a, 31b, 31c have the injection hole angle α defined above, and the injection hole angles α may all be the same or different from each other. The other configuration is the same as that of the first embodiment, and the area of the outlet is larger than the area of the inlet in the united injection hole 30, and the united injection hole 30 is formed by combining circular holes. Therefore, manufacture is easy.

  According to the experiment, the diameter of the nozzle hole 31b having the larger fistula diameter among the adjacent single nozzle holes 31b and 31c is D, and the distance between the centers of the outlets of the adjacent single nozzle holes 31b and 31c is ds (mm). Then, as shown in FIG. (D), the relationship between the spray average particle size (μm) and ds is such that when 0 <ds ≦ 3D / 4, the thinning of the fuel in the coalesced injection hole 30 is promoted, It can be seen that the desired spray particle size is obtained. Further, when ds> 3D / 4, it can be seen that a portion where each single injection hole intersects inhibits the spread of fuel in the combined injection hole, and a desired spray particle size cannot be obtained.

Embodiment 8 FIG.
FIG. 10 is a view showing an injection hole plate portion at a tip portion of a fuel injection valve according to Embodiment 8, in which (a) is a cross-sectional view, (b) is a plane explanatory view of FIG. (C) is a three-dimensional explanatory drawing of the J section of (b) figure. The single injection holes 35a, 35b, and 35c are continuously overlapped from the upstream side (upstream surface) to the downstream side (downstream surface) of the injection hole plate 11 to form the combined injection hole 32.

  The single injection holes 35a, 35b, and 35c are circular holes (cylindrical holes) having the same diameter from the upstream inlet portion to the downstream outlet portion of the injection hole plate 11, and the single injection holes 35a, 35b, and 35c. The fistula diameters may be different or the same. The single injection holes 35a, 35b, and 35c have the injection hole angle α defined above, and the injection hole angles α may all be the same or different from each other. The other configuration is the same as that of the first embodiment, and the area of the outlet is larger than the area of the inlet in the united injection hole 32, and the united injection hole 30 is formed by combining the circular holes. Therefore, manufacture is easy.

  In the eighth embodiment, the inner side of the virtual envelope 33 where the extension line of the seat surface 10a of the valve seat 10 that forms the fuel passage and decreases in diameter toward the downstream side intersects the upstream plane 11c of the nozzle hole plate 11 intersects. In addition, the inlet part of the united injection hole 32 is arranged, and the outlet part of the united injection hole 32 is arranged on the radially outer side of the valve seat shaft 34 with respect to the inlet part.

As shown in FIG. 10, by forming the fuel flow from the upstream side of the united injection hole 32, the main flow of the fuel flow from the valve seat portion 10 a is further strengthened, and the fuel in the united injection hole 32 is more Thinning and atomization are promoted.
In addition, this invention is not limited to the example shown in embodiment, A various design change is possible in the range which does not deviate from the summary.

DESCRIPTION OF SYMBOLS 1 Fuel injection valve 2 Solenoid apparatus 3 Housing 4 Core 5 Coil 6 Amateur 6a Amateur upper surface 7 Valve apparatus 8 Valve body 9 Valve main body 9a Guide part 10 Valve seat 10a Valve seat seat surface 10b Valve seat sliding part 11 Injection hole plate 11a, 11b Welded part

11c Injection hole plate upstream side plane 12 hole 13 Valve element tip 13a groove 13b guide part 14 compression spring 15a, 15b, 15c single injection hole 16 combined injection hole 16a combined injection hole inlet part 16b combined injection hole outlet part 17a, 17b , 17c Single injection hole 18 Combined fistula 19a Small particle size in the collective spray 19b Large particle size in the collective spray 20 Intake valve central portion 21 Inlet port inner wall

22 united hole 22a united hole inlet 23a, 23b, 23c single unit hole 24 united unit hole 25a, 25b, 25c unitary unit hole 26 united unit hole 27a, 27b single unit hole 28 united unit hole 29a, 29b , 29c Single injection hole 30 Combined injection hole 31a, 31b, 31c Single injection hole 32 Combined injection hole 33 Virtual envelope 34 Valve seat shaft 35a, 35b, 35c Single injection hole 51 Connector

Claims (9)

A valve body that opens and closes the valve seat, and by opening the valve seat with the valve body, the fuel passes between the valve body and the seat surface of the valve seat, and the jet mounted on the downstream side of the valve seat In the fuel injection valve that is injected from a plurality of holes provided in the hole plate,
The hole provided in the nozzle hole plate is a united nozzle hole formed by partially overlapping two or more single nozzle holes from the upstream side to the downstream side of the nozzle hole plate,
Each of the single nozzle holes is a circular hole having the same diameter at the inlet part on the upstream side and the outlet part on the downstream side of the nozzle hole plate,
At least one of the single nozzle holes has a nozzle hole angle α defined by an inclination angle of a central axis connecting the inlet center and the outlet center with respect to the nozzle plate thickness direction,
When projecting the central axis of each single nozzle hole forming the merged nozzle hole onto a plane perpendicular to the valve seat axis, the crossing angle is such that the central axes of the single nozzle holes intersect each other. By having β, the area of the outlet portion is larger than the area of the inlet portion in the coalesced injection hole,
The united injection hole is formed by press working.   2. The fuel injection valve according to claim 1, wherein the united nozzle holes have different diameters of the plurality of single nozzle holes forming the united nozzle holes.   The area of the inlet portion in the coalesced injection hole is made the same as the area of the inlet portion of the single fistula of the maximum fistula diameter among the plurality of single nozzle holes forming the coalesced fistula. The fuel injection valve according to claim 1 or 2.   2. The fuel injection valve according to claim 1, wherein the united injection hole has the same diameter of the plurality of single injection holes forming the same.   The fuel injection valve according to any one of claims 1 to 4, wherein the plurality of single injection holes have the same injection hole angle α.   The fuel injection valve according to any one of claims 1 to 4, wherein the plurality of single well holes have different injection hole angles α.   When the nozzle hole diameters D of the plurality of single nozzle holes forming the same are all the same, the distance between the centers of the outlet portions of the adjacent single nozzle holes is ds. 2. The fuel injection valve according to claim 1, wherein the adjacent single injection holes are partially overlapped so as to satisfy ds ≦ D / 2.   The unitary injection hole is an injection having a larger fistula diameter in the adjacent single injection holes when the injection hole diameters of the plurality of single injection holes forming the same are different in the adjacent single injection holes. When the hole diameter is D and the distance between the centers of the outlet portions of the adjacent single nozzle holes is ds, the adjacent single nozzle holes are partially overlapped so that 0 <ds ≦ 3D / 4. The fuel injection valve according to any one of claims 1 to 3, wherein the fuel injection valve is configured as described above.   The inlet portion of the united injection hole is a virtual envelope in which an extension line of the valve seat surface of the valve seat that forms a fuel passage and is reduced in diameter toward the downstream side intersects with an upstream plane of the injection hole plate 9, and the outlet portion of the coalesced injection hole is disposed radially outside the valve seat shaft with respect to the inlet portion. The fuel injection valve described in 1.

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